1. Technical Field
The present invention relates to an immersion heater, for example, for use in heating equipment for molten metal such as an aluminum holding furnace, and particularly relates to an immersion heater including a metal heating element of an Fe—Cr—Al based alloy or the like.
2. Description of the Related Art
Conventionally, as an immersion heater for use in molten metal such as molten aluminum, there has been an immersion heater employing a metal heating element. For example, in Japanese Utility Model Application Laid-Open No. 5-21275, there is disclosed an immersion heater having an insulating cylindrical body arranged so as to be suspended inside a ceramic protecting tube (immersion tube) having a bottomed cylindrical shape, a wire heating element (heating part) having a circular cross section arranged inside a spiral groove formed in an outer circumference portion of this insulating cylindrical body, and an insulating cover closing an opening end of the ceramic protecting tube, and one end of each terminal rod is connected to the wire heating element, and the other end of the terminal rod passes through the insulating cover.